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CN-122010192-A - Preparation method of large-particle-size nickel hydroxide

CN122010192ACN 122010192 ACN122010192 ACN 122010192ACN-122010192-A

Abstract

The invention discloses a preparation method of large-particle-size nickel hydroxide in the field of inorganic functional materials, which realizes particle size control by a strategy of combining stepwise parallel flow charging and guiding agent regulation. Firstly, in the reaction base liquor containing ammonia water and the guide agent, synchronously dripping nickel salt and alkali liquor with higher concentration, under the weak alkaline condition, uniformly producing crystal nucleus and ageing, then synchronously dripping nickel salt and alkali liquor with lower concentration, under the slightly strong alkaline condition, making crystal nucleus implement epitaxial growth, finally ageing, washing and drying so as to obtain the invented product. The guiding agent is prepared by activating vanadium pentoxide with hydrogen peroxide, reacting with cesium carbonate, performing hydrothermal crystallization to prepare layered cesium vanadate, and performing surface modification with a silane coupling agent. The heterogeneous nucleation and growth guiding effect of the guiding agent are utilized, the two-step feeding process is cooperated, homogeneous nucleation is effectively inhibited, controllable synthesis of nickel hydroxide particle size within a target range is realized, and the process is stable and good in repeatability.

Inventors

  • WANG LINGYUN
  • WANG XIAOPEI
  • CHEN JIANFENG

Assignees

  • 怀化炯诚新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. The preparation method of the nickel hydroxide with large particle size is characterized by comprising the following steps: S1, adding 1500-2500 parts of deionized water into a reaction kettle, heating to 54-56 ℃, adding 0.3-0.7 part of cesium vanadate intercalation guiding agent, adding 6.2-8.5 parts of ammonia water, and continuously stirring to obtain a mixed solution; S2, adding 1.4-1.6mol/L nickel sulfate aqueous solution and 2.4-2.6mol/L sodium hydroxide aqueous solution into the mixed solution, regulating the pH to 11.2-11.4, stirring and aging; s3, adding 0.9-1.1mol/L nickel sulfate aqueous solution and 1.6-2.0mol/L sodium hydroxide aqueous solution into a reaction kettle, regulating the pH value to 11.5-11.7, stirring, and aging; S4, maintaining the temperature of the reaction kettle at 54-56 ℃, stirring, aging to obtain slurry, cooling the slurry to room temperature, performing solid-liquid separation by using a plate-and-frame filter press to obtain a filter cake, washing the filter cake by using deionized water at 78-82 ℃, and finally drying in a vacuum drying oven at 104-106 ℃.
  2. 2. The method for producing large particle size nickel hydroxide according to claim 1, wherein in step S1, the ammonia concentration in the mixed solution is 7.8 to 8.2g/L.
  3. 3. The method of producing large particle size nickel hydroxide according to claim 1, wherein the aging time in step S2 is 30 to 60 minutes.
  4. 4. The method for producing large particle size nickel hydroxide according to claim 1, wherein the stirring time in step S3 is 20 to 40 minutes.
  5. 5. The method according to claim 1, wherein in step S4, the drying time in a vacuum drying oven at 104 to 106 ℃ is 12 to 14 hours.
  6. 6. The method for producing large particle size nickel hydroxide according to any one of claims 1-5, wherein the cesium vanadate intercalation guide agent is produced by: Adding 5-7 parts by weight of vanadium pentoxide into 200-400 parts by weight of deionized water, stirring to obtain a suspension, dropwise adding 15-25 parts by weight of hydrogen peroxide solution into the suspension under stirring to obtain a mixture, continuously stirring the mixture at 68-72 ℃ to obtain gel, centrifugally washing the gel with deionized water, and re-dispersing the gel in the deionized water to obtain vanadium pentoxide sol; A2, dropwise adding a solution of 3-6 parts of cesium carbonate dissolved in 30-60 parts of deionized water into vanadium pentoxide sol under stirring, adjusting the pH value to 10-11, and continuing stirring at room temperature after the dropwise adding is finished to obtain a mixture; A3, transferring the mixture into a high-pressure reaction kettle, sealing the high-pressure reaction kettle, placing the high-pressure reaction kettle into a blast drying oven, performing hydrothermal reaction at 175-185 ℃, naturally cooling to room temperature after the reaction is finished, discarding supernatant of the high-pressure reaction kettle, alternately centrifuging and washing sediment at the lower layer of the high-pressure reaction kettle by using deionized water and absolute ethyl alcohol to obtain a washed sediment; A4, transferring the nano-sheet dispersion liquid into a three-necked flask, heating to 58-62 ℃ under the protection of nitrogen, adding 1.5-2.5 parts of 3-aminopropyl triethoxysilane, stirring for reaction to obtain a reaction mixture, centrifuging the reaction mixture to obtain a solid product, washing the solid product with ethanol, and freeze-drying.
  7. 7. The method for producing large particle size nickel hydroxide according to claim 6, wherein in step A1, the mixture is kept under stirring at 68 to 72℃for 24 to 30 hours.
  8. 8. The method of producing large particle size nickel hydroxide according to claim 6, wherein in step A2, stirring is continued at room temperature for 12 to 14 hours.
  9. 9. The method of producing large particle size nickel hydroxide according to claim 6, wherein the time of the ultrasonic treatment in step A3 is 1 to 2 hours.
  10. 10. The method for producing large particle size nickel hydroxide according to claim 6, wherein in step A4, the stirring reaction is performed for a period of 6 to 8 hours.

Description

Preparation method of large-particle-size nickel hydroxide Technical Field The invention relates to the technical field of inorganic functional materials, in particular to a preparation method of nickel hydroxide with large particle size. Background Nickel hydroxide, an important inorganic functional material, plays an irreplaceable role in the field of alkaline secondary batteries, and is a key component of positive electrode active materials of batteries such as nickel-cadmium, nickel-hydrogen, nickel-zinc and the like. The physical and chemical properties, especially the crystal structure, particle morphology, particle size and distribution, directly determine the packing density of the electrode, the utilization rate of active substances, and the overall energy density and cycle life of the battery. The large-particle-size, high-density and spherical nickel hydroxide can obviously improve the tap density of an electrode, reduce the volume in the battery assembly process, improve the specific volume, and simultaneously is beneficial to improving the wettability and the charge transmission efficiency of electrolyte, so that the nickel hydroxide is always an important direction for developing high-performance alkaline battery materials. The market has clear demands for nickel hydroxide products with particle sizes on the order of tens to hundreds of micrometers and concentrated distribution, which puts high demands on the preparation process that the grain growth is controllable and the products are uniform and stable. Currently, industrial large-scale nickel hydroxide preparation mainly adopts a chemical precipitation method, wherein a continuous coprecipitation method and an improved process thereof are most common. To achieve the desired particle size and morphology, the skilled artisan has developed a variety of control strategies. One basic method is single-step co-current precipitation, which affects the crystallization process by controlling macroscopic parameters such as reaction temperature, acid-base concentration, feed rate and stirring intensity, but the method has limited control over nucleation and growth separation, and can easily obtain products with wide particle size distribution. The more advanced idea is a sectional feeding method, namely, firstly, a large number of crystal nuclei are promoted to be generated rapidly under specific conditions, and then, the reaction conditions are changed to ensure that newly-added materials are deposited and grown on the surfaces of the existing crystal nuclei preferentially, so that the expansion of the particle size is realized. In addition, the particle size distribution can be further refined by aging for a long time after the completion of the reaction and utilizing the ostwald ripening effect of dissolution and recrystallization. Although these traditional methods are constantly optimized, there are some inherent technical bottlenecks. For example, it is difficult to completely inhibit the continuous occurrence of homogeneous nucleation in the nucleation stage, so that new nuclei still remain in the growth stage to affect the uniformity of the final particle size, the aging process takes a long time, usually several hours or more, the production efficiency is required to be improved, and in order to regulate the performance, other metal elements such as cobalt, zinc and the like are required to be doped in the precipitation process, thereby increasing the cost of raw materials and the complexity of the process. These factors limit the accuracy, economy and consistency of the preparation of high performance large particle size nickel hydroxide products. Aiming at the defects of the prior art, the invention aims to provide an innovative preparation method of nickel hydroxide with large particle size. The core of the invention is to introduce cesium vanadate intercalation guiding agent and creatively combine the cesium vanadate intercalation guiding agent with a classical two-stage charging and precipitation process. The guiding agent is not directly involved in forming a final product, but is used as a template and a regulator in the crystallization process, the unique layered structure and the surface characteristics of the guiding agent can strongly adsorb nickel ions, and rich and uniform heterogeneous nucleation sites are provided, so that the effective control of the number and the positions of crystal nuclei is realized from the source, and unnecessary homogeneous nucleation is greatly inhibited. On the basis of the guiding effect, a well-designed two-stage feeding strategy is combined, wherein the first stage generates uniform and dense initial crystal nuclei in a weak alkaline environment, and the second stage guides newly generated nickel hydroxide to directionally cover the crystal nuclei for epitaxial growth in an adjusted alkaline environment. The method not only reduces the sensitivity to the fluctuation of the traditional process para